Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5b89035c835fd10…

MALICIOUS

PDF

106.1 KB
MD5: 90984bb2b4709d241608a9a08cb3aba7 SHA-1: 8f65792ff681b61943a045c19f181ed51d7ddfb9 SHA-256: b5b89035c835fd105d1d133b5a562484df4e3421018dd3be4c202345d7c06853
418 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/Shell Script: JavaScript T1204.002 Malicious File: User Execution: Malicious File

The PDF file contains embedded JavaScript that is heavily obfuscated using a character table indexing technique. This JavaScript is designed to exploit several known vulnerabilities in older versions of Adobe Reader, specifically targeting functions like media.newPlayer, Collab.getIcon, Collab.collectEmailInfo, and util.printf. The primary goal appears to be the execution of arbitrary code, likely to download and run a secondary payload.

Heuristics 10

  • media.newPlayer — CVE-2009-4324 critical CVE exact CVE_2009_4324
    PDF JavaScript calls media.newPlayer — CVE-2009-4324 is a use-after-free in Adobe Reader's multimedia plugin triggered by media.newPlayer(). Actively exploited as a zero-day in December 2009. (identified after JavaScript deobfuscation)
  • Collab.getIcon — CVE-2009-0927 critical CVE exact CVE_2009_0927
    PDF JavaScript calls Collab.getIcon — CVE-2009-0927 is a stack buffer overflow in Adobe Reader triggered by Collab.getIcon() with a crafted argument. Allows arbitrary code execution. (identified after JavaScript deobfuscation)
  • Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659
    PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (identified after JavaScript deobfuscation)
  • util.printf — CVE-2008-2992 critical CVE exact CVE_2008_2992
    PDF JavaScript calls util.printf() — CVE-2008-2992 is a stack buffer overflow in Adobe Reader triggered by a long format-specifier argument. Widely exploited in the wild after disclosure. (identified after JavaScript deobfuscation)
  • ClamAV: Pdf.Exploit.Agent-36749 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36749
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • Character-table JavaScript eval stager high PDF_JS_CHAR_TABLE_EVAL_STAGER
    PDF JavaScript reconstructs an exploit stage by indexing into a small character table, appending hundreds of one-character fragments, joining the array, and evaluating the result. This static fallback fires only after the bounded decoder recovers an exploit-like stage, so it catches this obfuscation even when no single CVE API signature is available.
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0076_000.js
fd2dc0b57d640b8a1d81aed9ebace09d35b16bead087ea566143c8adde3a2579
pdf-javascript-stream PDF /JS object 76 at offset 0x2C2 107797 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36749
Obfuscation or payload: unlikely
char_table_stage_000.js
5a9614c82abe819af7bc7f9fe0469e83872f3ef59330305c4c2c004d9ff62894
deobfuscated-js char-table indexed JavaScript (PDF /JS object 76) at offset 0x2F1 3858 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).